The contractor will supply the following antiserum reagents in quantities of 100 ml: anti-immunoglobulin reagents with specificities of alpha, gamma, mx, delta, and epsilon human heavy chains; kappa and lambda light chains; Fc and Fab of human IgG; mouse alpha, gamm 1, famma 2a, gamma 2b, and mx heavy chains; mouse kappa and lambda light chains; and Fc and Fab fragments of mouse IgG. We will also prepare antisera specific for human T and B cells. We will prepare F(ab')2 fragments of those antibodies the project officer deems desirable. We will conjugate selected antisera at fluorescein:protein molar ratios of approximately two to one, and test these fluoresceinated conjugated for specificity at the fluorescence level.